code: def setUp(self):
      super().setUp()
  
      # We have a SentencePiece fixture for testing
      tokenizer = MBart50Tokenizer(
          SAMPLE_VOCAB,
          src_lang="en_XX",
          tgt_lang="ro_RO",
          keep_accents=True,
      )
      tokenizer.save_pretrained(self.tmpdirname)
  
imports: import shutil
  import tempfile
  import unittest
  from transformers import SPIECE_UNDERLINE, BatchEncoding, MBart50Tokenizer, MBart50TokenizerFast, is_torch_available
  from transformers.testing_utils import get_tests_dir, nested_simplify, require_sentencepiece, require_tokenizers, require_torch, slow
  from ...test_tokenization_common import TokenizerTesterMixin
label_desc: Use image node_id 1 for calling the MBart50TokenizationTest obj's underlying member method code with example usage: obj.setUp() without return types